The Walnut, is any tree of the genus Juglans which belong to the Beech family, or fagaceae Two common members of the walnut family are the English walnut, Juglans regia and the black walnut Juglans nigra. The English walnut is, compared to other trees in its family, a fast growing tree, which makes walnut wood a soft material compared to oak. The Black walnut is slower growing and the wood harder, but it is still highly valued for its durability and unique colour.
The nut of both species are edible, but the walnuts commonly available in stores are the English walnut.